Fuze for bombs, projectiles, and the like



April 8, 194?. H. c. HEBARD FUZE FOR BOMBS, PROJECTILES, AND THE LIKE Filed March 20, 1945 ATTORNEYS R O T N E V N C m/W Patented Apr. 8, 1947 EN'l' OFFICE- FUZE FOR non/ms, PROJECTILES, AND

THE

LIKE

Hugh Charles Hebard, N orthwood, England Application March 20, 1943, Serial No. 479,938 In Great Britain June 13, 1941 3 Claims. -1

This invention relates to fuzes for bombs, projectiles, flares and the like and has for its object to provide an improved form of fuze and method of manufacturing the same, the said fuze being more particularly designed for use where adjustment may be necessary to vary the predetermined time period which elapses before explosion or ignition of a charge as well as to ensure quick melting of the fuze coating and certain ignition of the secondary fuze or other combustible component. The invention is particularly designed to avoid the unsatisfactory practice of piercin fuzes.

According to the present invention a fuze for bombs, projectiles, flares and the like is provided comprising a core of combustible material surrounded by a metallic sheath, at least one side or edge of which is of relative thinness as compared with the remaining part of the sheath. The thinness of the wall of the side or edge ensures that, as the fuze burns, a flame emerges from the sheath and travels uniformly along the thin wall. This thinness may be achieved by rolling a fuze of initially circular cross section to produce a fuze having two parallel thin sides or by removing a portion of the metal covering and by rolling to produce a fuze having one thin side.

Reference will now be made to the accompanying drawings which illustrate diagrammatically and on an enlarged scale examples of fuzes formed according to the invention and in which:

Fig. 1 is a cross section of a fuze which has been formed with two thin sides,

Fig. 2 is a cross section of a fuse which has been formed with one thin side,

Fig. 3 is a cross section of the fuze shown in Fig. 2 at one stage of manufacture and Fig. 4 is a perspective view to illustrate one application of the invention.

In carrying the invention into effect and in the preferred manner, the improved fuze consists of a slow burning core a, Fig. 1, which is provided with a coating b of lead or other low fusible metal alloy. This fuze can conveniently be formed from a lead sheathed fuze of known type and of initially circular cross section which is subjected to a rolling operation to produce a substantially flat condition in which the fuze has the cross sectional form shown in Fig. 1. In this form the core a is covered on the flat surfaces 0 with thin coatings d of metal while the edges e are thickened by the rolling operation. When lead is the metal used for the coating the portions 0 should not be more than fifteen thousandths of an inch in thickness. By making the fuze with two thinned sides an advantage is obtained in assembly as the ribbon-like fuze can be fitted into its channel in the fuze magazine either way round. This form of fuze is intended to be mounted with the wall opposite a thin side in contact with the bottom of a metal channel. This contact cools this side of the sheath and ensures rapid melting and emergence of a uniformly travelling flame from the exposed side. This ensures that a second fuze or other combustible material for the purpose of igniting a flare charge or the like is ignited. The amount of fuze with thinned wall burned before ignition of the second fuze is variable and determines the time of delay. One method of achieving this is illustrated in Fig. 4 wherein g indicates the metal channel in which a fuze made according to the invention is disposed with a thin surface (1 uppermost, the illustration showing how the buming fuze flashes onto a second fuze h which can be of normal circular cross section and which in turn ignites the explosive charge or a flare charge.

In cases where the construction of the fuze magazine or the like precludes the use of a fuze having two thin walls, the construction of fuze shown in cross section in Fig. 2 can be employed.

. tion at right angles to the surface j until a fuze is produced having substantially the cross section shown in Fig. 2.

I claim:

1. A fuse comprising'an elongated core composed of combustible material, and a flat tubular sheath of low fusing point metal surrounding and extending longitudinally of the core, the thickness of the sheath along at least one side thereof being less than its thickness along its edges.

2. A fuse comprising a core of combustible material, and a flattened tubular sheath of low fusing point metal surrounding the core, one of the flattened sides of the sheath being of less thickness than that of the other flattened side and the edges thereof.

3. A fuse comprising a core of combustible material, and a flattened tubular sheath of low fusing point metal surrounding the core, the two flattened sides of the sheath being of less thickness than that of the edges thereof.

HUGH CHARLES HEBARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 43,922 McDevitt Aug. 23, 1864 200,223 Rubin Feb. 12, 1878 882,154 Lheure Mar. 17, 1908 1,923,761 Snelling et a1 Aug. 22, 1933 2,083,174 Snelling June 8, 1937 FOREIGN PATENTS Number Country Date 171,091 British Jan. 10,1922 149,738 British Aug. 16, 1920 

